I have similar experiences to magiccarpet, though I also experience chronic itchininess ALL OVER, or possibly more sensitivity to it, if I stay up for around 30 hours straight... I also feel cold in some places, but ridiculously warm in others... SO disorientating.
After staying up for around 35 hours or more, I usually start hallucinating and entering a hypnopompic state quite readily, as my body tries to send me to sleep... Its VERY disturbing and I do not reccomend it..
I generally also have a short temper when I dont sleep much...
Though, I think I could live comfortably with 6 hours a night for the rest of my life, 8 is far better for me!!